A new ruler on the Kisei Throne (**-*****)

In the professional go world in Japan, three great titles clearly stand out in prestige and money offered-Kisei, Meijin, and Honinbo, with 33 million yen, 28 million yen and 25 million yen in prize money, respectively. Cho Chikun, a South Korean who came to Japan at the age of 6, held these three titles at the same time since 1996 to earn yearly prize money in excess of 100 million yen. Last year, he lost the Honinbo title to 30-year-old fellow countryman Cho Sonjin, who up to then was a relatively unknown player.

Cho Chikun had held the Honinbo title for 10 straight years. Last month, Cho had his much treasured Kisei title taken from him after holding it for eight of its 24 years of existence. The new titleholder is O Rissei who was born in Taiwan and came to Japan when he was 12 years old. Although O had been expected to make a major impact in Japan's go world, for years he only won some minor titles. Becoming the new Kisei clearly marked a peak in his professional career, which spans almost 30 years. Asked how he felt about winning, O said that the day he won the title was the happiest day of his life.

Semeai and Tesuji

Problem 1 shows a corner position we will solve over the next few weeks by studying semeai and tesuji. The problem is whether black 1 is the correct move. Hint: A multistep ko is a step toward the solution.

But before starting with this problem, let's first have a look at some more semeai and tesuji starting with the two other problems set last week.

Solution 2 for last week's problem 2: In preparation for the semeai, white 1 will slow down Black. If Black answers with 2, White then wins the semeai, a result that becomes clear when he plays at 9. At this stage, Black wants to play at A, but then his three corner stones will be taken by white B. Therefore, Black has to play at B first in order to play at A. By that time White will play at C and D and capture the six marked Black stones.

Reference 2A: If White begins the capturing race without the preparatory move of 1 in solution 2, White will find himself holding the short end of the stick and his seven marked stones will be captured when Black plays 8.

Reference 2B: Black 2 is a good response to white 1. When White starts the semeai now, the sequence to 7 follows, but now Black can start a ko with 8. Fortunately, White is the first to capture the ko with 9, putting Black at a disadvantage. Besides, Black stands to lose points if he plays the ko as White can capture at A and lay waste to Black's territory. So, Black will probably leave the situation as is after white 3 and wait until he has created sufficiently large ko threats to start the ko.

Solution 3A for last week's Problem 3: By playing at 1, White extends his liberties. Black has no choice but to submit with 2. In the sequence to 13, White easily wins the semeai.

Solution 3B: Actually, after white 7, Black can stir up some trouble with 8. This does not really slow down White as he can now play 9, 11, and 13, which will put the black stones in atari one move earlier.

This is a kind of ko. During the ko fight, Black will have to ignore some ko threats and play good ko threats himself as he slowly makes his approach moves.

Now try to solve the problem at the beginning of the article and the two below:

Problem 1: Remember that making eyes or forestalling them is a winning tactic in many semeai.

Problem 2: White to play and capture the marked black stones.

Problem 3: White has just played at 1. How does Black take advantage of this move and capture the marked white stones ?